Stem rust caused by Puccinia graminis f. sp. tritici Eriks and Henn and leaf rust caused by Puccinia triticina Rob. ex Desm. are major constraints to wheat production worldwide. In the present study, F(4)-derived SSD population, developed from a cross between Australian cultivars 'Schomburgk' and 'Yarralinka', was used to identify molecular markers linked to rust resistance genes Lr 3 a and Sr 22. A total of 1,330 RAPD and 100 ISSR primers and 33 SSR primer pairs selected ob the basis of chromosomal locations of these genes were used. The ISSR marker UBC 840(540) was found to be linked with Lr 3 a in repulsion at a distance of 6.0 cM. Markers cfa 2019 and cfa 2123 flanked Sr 22 at a distance of 5.9 cM (distal) and 6.0 cM (proximal), respectively. The use of these markers in combination would predict the presence or absence of Sr 22 in breeding populations. A previously identified PCR-based diagnostic marker STS 638 linked to Lr 20 was validated in this population. This marker showed a recombination value of 7.1 cM with Lr 20.

BackgroundRove beetles of the genus Paederus cause dermatitis when they come in contact with human skin. This condition is prevalent in some tropical and subtropical regions, such as in northern Pakistan, where it was recorded for the first time by US troops. Despite much research from other countries on this subject, few studies, mostly clinical, have been performed in a Pakistani context. A survey was carried out in villages, towns and cities of Punjab province, Pakistan, to explore the rove beetle population dynamics and to develop a model to elucidate the symptoms, preventive measures and treatment strategies for this dermatitis.MethodsThe prospective observational and patient surveys were performed bimonthly over a period of two years, in different districts of Punjab province. Collection was carried out in fields, gardens and houses during every visit with the aid of a pitfall trap, light trap, flight intercept trap, Berlese funnel trap and sweep netting. These traps were installed for four days during every visit. Interviews of ten individuals of different ages and sexes from each site were recorded during each visit.ResultsOut of 980 individuals, 26.4% were found to suffer from Paederus dermatitis. Lesions were most commonly found on the neck followed by the face. In July-August during the rainy season, this skin irritation was most prevalent and the population of these beetles peaked (36.2%). During May-June, the beetle population was lowest (7.85%) due to soil dryness. About 70% of such irritation cases were from individuals living in farming villages or in farmhouses. Their houses typically (80%) had broken doors and screen-less windows while 97% of the residents were unaware of how they may have come into contact with these beetles. In most cases (91% from villages/small towns and 24% from cities and adjoining areas) the local residents were unaware of modern treatment strategies.ConclusionsPaederus dermatitis is extremely frequent in villages with poor housing facilities and could be avoided via community awareness.

The green peach aphid, Myzus persicae Sulzer (Hemiptera: Aphididae), a polyphagous insect pest is a major threat to a wide range of crops worldwide. Aiming to evaluate the life history traits of M. persicae, feeding on different host plants, we used five vegetables: cabbage, Brassica oleracea (Brassicaceae); chinese cabbage, B. rapa (Brassicaceae); chili pepper, Capsicum annum (Solanaceae); crown daisy, Chrysanthemum coronarium (Asteraceae); and eggplant, Solanum melongena (Solanaceae). TWOSEX-MSchart software was used for the statistical analysis about the age-stage, two-sex life table theory. The highest fecundity (69.65 individuals) rate of M. persicae, intrinsic rate of increase (r = 0.425 d−1), finite rate of increase (λ = 1.531 d−1), net reproductive rate (R0 = 69.65 offspring), and shortest mean generation time (T = 9.964 d) were recorded on the chili pepper plant. Whereas, lower fitness occurred on cabbage. The findings attained from population growth parameters indicate that chili pepper is the most susceptible plant, while cabbage is resistant to aphids. Population projection results also supported this statement, as the final total population size on cabbage was significantly lower than other plants. The reported information would be useful for devising integrated pest management programs, particularly those involving M. persicae. This information also suggests the adaptability of M. persicae causing economic damage to these vegetable cultivars.

Two entomopathogenic nematodes (EPNs) Heterorhabditis indica and Steinernema carpocapsae were tested against the armyworm, Spodoptera litura (F.) (Lepidoptera: Noctuidae). Also, their compatibility with spinosad (Tracer® 240SC) was assessed under laboratory conditions. In study I, compatibility test was performed to evaluate the viability of nematodes at different concentrations of spinosad. None of the concentrations was observed as toxic against both EPNs. The highest concentration (800 ppm) of the spinosad showed 14% mortality in H. indica juveniles and 13% in S. carpocapsae 48 h post-treatment. In study II, the spinosad and the EPN mixtures showed that both EPNs enhanced the efficacy of spinosad against S. litura larvae. The highest mortality rates (80.0 and 76. 6%) in the second instar larvae indicated a synergistic effect (χ 2 = 39.69 and 7.02) 48 h post-treatment, with infective juveniles (IJs) of S. carpocapsae and H. indica, respectively, with the highest concentration of spinosad. In the case of the third instar larvae, a synergistic effect (χ 2 = 16.73) was observed in H. indica and the highest concentration of spinosad, while other treatments showed additive efficacy of the EPNs. After 96 h, all treatments exhibited synergistic effect, except when H. indica was applied at the lowest concentration of spinosad. However, these combination treatments need to be tested further with EPNs under field conditions to confirm their efficacy.

Despite of extensive application of insecticides, severe infestation of date palms is reported with Ommatissus lybicus every year. The development of insecticide resistance in the field strains receiving heavy pesticide regimes can be a reason for unsuccessful control. Seventeen field strains of O . lybicus from Oman were appraised for resistance against deltamethrin and fenitrothion in years 2017 and 2018. Eleven field strains depicted susceptibility (RR < 3-fold) while six strains expressed minor (RR = 3–5-fold) to low level (RR = 5–10-fold) of resistance against deltamethrin when compared with lab-susceptible strain. In case of fenitrothion, fourteen field strains exhibited minor to low level of resistance and only two showed susceptibility. Intermediate resistance (RR = 10–40-fold) was also reported in one field strain against fenitrothion. A significant but low resistance (RR = 7.86-fold) was observed in a lab strain selected with deltamethrin for resistance development mechanism studies. The deltamethrin-selected strain exhibited minor resistance development (RR = 3.13-fold) against fenitrothion. Significant reduction in resistance was observed with higher toxicity values when the two pesticides were tested along with piperonyl butoxide (PBO) against all the field collected dubas bug strains. Higher susceptibility of field strains to deltamethrin suggest it a suitable alternate candidate to deter resistance development in O . lybicus .